Wells score in the clinical prediction of pulmonary embolus (PE)

Wells et al developed a simple clinical model which was able to predict the possibility of a patient having a PE.

It contained 7 variables with a total score of 12.5 points

• predisposing factors
  • previous DVT or PE - 1.5 points
  • recent surgery or immobilization - 1.5 points
  • cancer - 1 point
• symptoms
  • haemoptysis - 1 point
• clinical signs
  • heart rate >100 beats/min - 1.5 points
  • clinical signs of DVT - 3 points
• clinical judgement
  • alternative diagnosis less likely than PE - 3 points

The clinical probability can be divided according to the points scored into:

• three-category scheme
  • low 0-1 points
  • intermediate 2-6 points
  • high 7 or more points
    
    
• two-category scheme
  • PE unlikely 0-4 points
  • PE likely >4 points

The two category (two level) Well's score is used by NICE (2).

Reference:

• 1. Torbicki A et al. Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J. 2008;29(18):2276-315.
• 2. NICE (June 2012). Venous thromboembolic diseases: the management of venous thromboembolic diseases and the role of thrombophilia testing